ASSOCIATION OF NEUTROPHIL-LYMPHOCYTE RATIO AND C-REACTIVE PROTEIN LEVELS WITH DISEASE SEVERITY IN CHILDREN WITH BRONCHIOLITIS: A PROSPECTIVE OBSERVATIONAL STUDY

Abstract

Background:
Bronchiolitis is a major cause of hospitalization in infants, particularly during the viral season. While clinical assessment remains the mainstay for diagnosis and management, the need for objective laboratory markers to predict disease severity is increasingly recognized. The Neutrophil-to-Lymphocyte Ratio (NLR) and C-Reactive Protein (CRP) are simple, cost-effective biomarkers that reflect systemic inflammation and immune response.

Objectives:
This study aimed to determine the association between NLR and CRP levels with clinical severity in infants diagnosed with bronchiolitis.

Methods:
A prospective observational study was conducted at a tertiary care hospital in India. A total of 120 children aged below 24 months diagnosed with bronchiolitis were enrolled. Based on the Bronchiolitis Severity Score (range: 7–21), patients were categorized into mild (n=46), moderate (n=52), and severe (n=22) groups. NLR was calculated from the differential leukocyte count, and serum CRP levels were measured. Statistical analysis included ANOVA and ROC curve analysis.

Results:
Mean NLR and CRP values increased progressively with disease severity (NLR: 1.9, 3.3, 5.7; CRP: 4.0, 8.8, 13.6 mg/L respectively; p<0.001). ROC analysis showed NLR >3.7 had 88.2% sensitivity and 81.3% specificity (AUC=0.84), while CRP >9.5 mg/L yielded 81.8% sensitivity and 72.0% specificity (AUC=0.79). Severe bronchiolitis correlated with feeding difficulty, oxygen desaturation, and prolonged hospital stay.

Conclusion:
Both NLR and CRP serve as valuable adjunctive markers for predicting bronchiolitis severity, aiding in early risk stratification and clinical decision-making.